Westlands Water District Groundwater Warren Act Contract
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Draft Environmental Assessment Westlands Water District Groundwater Warren Act Contract EA-15-001 U.S. Department of the Interior Bureau of Reclamation March 2015 Mission Statements The mission of the Department of the Interior is to protect and manage the Nation’s natural resources and cultural heritage; provide scientific and other information about those resources; and honor its trust responsibilities or special commitments to American Indians, Alaska Natives, and affiliated island communities. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. Draft EA-15-001 Contents Page Section 1 Introduction ................................................................................... 1 1.1 Need for the Proposed Action ............................................................... 1 Section 2 Alternatives Including the Proposed Action............................... 3 2.1 No Action Alternative ........................................................................... 3 2.2 Proposed Action .................................................................................... 3 2.2.1 Environmental Commitments ......................................................... 6 Section 3 Affected Environment and Environmental Consequences ....... 9 3.1 Resources Eliminated from Further Analysis ....................................... 9 3.2 Water Resources ................................................................................... 9 3.2.1 Affected Environment ..................................................................... 9 3.2.2 Environmental Consequences ....................................................... 16 3.3 Land Use ............................................................................................. 19 3.3.1 Affected Environment ................................................................... 19 3.3.2 Environmental Consequences ....................................................... 20 3.4 Biological Resources .......................................................................... 20 3.4.1 Affected Environment ................................................................... 20 3.4.2 Environmental Consequences ....................................................... 29 3.5 Environmental Justice ......................................................................... 30 3.5.1 Affected Environment ................................................................... 30 3.5.2 Environmental Consequences ....................................................... 30 Section 4 Consultation and Coordination ................................................. 31 4.1 Public Review Period .......................................................................... 31 Section 5 Preparers and Reviewers ........................................................... 33 5.1 Reclamation ........................................................................................ 33 5.2 Westlands Water District .................................................................... 33 Section 6 References .................................................................................... 35 Figure 1-1 Project Location .................................................................................... 2 Figure 3-1 Mendota Pool Location ....................................................................... 11 Figure 3-2 Drainage-Impaired Lands .................................................................... 15 Figure 3-3 Areas of Known Historical and Estimated Future Subsidence ........... 17 Table 2-1 Proposed Discharge Locations ............................................................... 4 Table 2-2 Environmental Protection Measures and Commitments ........................ 7 Table 3-1 Resources Eliminated from Further Analysis......................................... 9 Table 3-2 Westlands Water District Historical Groundwater Pumping Data ....... 13 Table 3-3 Agricultural Products by County .......................................................... 19 Table 3-4 Federally Listed Species and Critical Habitat ...................................... 21 Table 3-5 Demographic Data, 2013 ...................................................................... 30 iii Appendix A Source Well Locations Appendix B Indian Trust Assets Determination Appendix C Cultural Resources Determination Draft EA-15-001 Section 1 Introduction 1.1 Need for the Proposed Action The State of California is experiencing unprecedented water management challenges due to severe drought in recent years. Both the State and Federal water projects are forecasting very low storage conditions in all major reservoirs. In addition, South of Delta Central Valley Project (CVP) contractors experienced reduced water supply allocations from 2007 to 2013 due to hydrologic conditions and regulatory requirements. Based on hydrologic conditions, Reclamation declared a 0% allocation for South of Delta CVP contractors for the 2014 Contract Year1. Although there has been some precipitation in the last few months, the drought is expected to continue into the 2015 Contract Year. As a result, South of Delta CVP contractors, such as Westlands Water District, have a need to make the most and best use of limited available supplies. In order to better manage available water, Westlands Water District has requested a Warren Act Contract to convey non-CVP water in the San Luis Canal for delivery to their in-district agricultural users. They have also requested the flexibility to perform operational exchanges of their available CVP supplies within San Luis Reservoir for storage of the non-CVP water within the reservoir and/or for delivery to agricultural users located upstream of the points of introduction. The purpose of the proposed Warren Act Contract is to convey pumped groundwater and other sources of non-CVP water to areas within the district that could not otherwise receive this water, providing greater water management flexibility to the district and their water users. 1 A Contract Year is from March 1 through February 28/29 of the following year. 1 Draft EA-15-001 Figure 1-1 Project Location 2 Draft EA-15-001 Section 2 Alternatives Including the Proposed Action This Environmental Assessment (EA) considers two possible actions: the No Action Alternative and the Proposed Action. The No Action Alternative reflects future conditions without the Proposed Action and serves as a basis of comparison for determining potential effects to the human environment. 2.1 No Action Alternative Under the No Action Alternative, Reclamation would not issue a Warren Act Contract to Westlands Water District for the introduction of their non-CVP water into the San Luis Canal. As Westlands Water District has an active groundwater pumping program, groundwater would still be pumped out of the aquifer as it has in the past. However, distribution of the non-CVP water would be limited to only those areas that could normally receive the water and would not enable Westlands Water District to provide water supplies to other areas in-district. 2.2 Proposed Action Reclamation proposes to enter into a five-year Warren Act Contract with Westlands Water District. Under the terms of the contract, Westlands Water District would introduce up to 30,000 acre-feet per year (AF/y) of non-CVP water into the San Luis Canal, in years in which Westlands Water District’s CVP allocation is 20% or less. The period of introduction would be between April 1 and August 31 of a given year. However, if it is not possible to begin conveyance by April 1, 2015, the conveyance period for this year would be shifted by one month, to between May 1 and September 30. All subsequent years would use the April 1 to August 31 window. The source of the non-CVP water would be pumped groundwater from deep groundwater wells within Westlands Water District, as well as other sources of non-CVP water by way of the Mendota Pool. Potential groundwater sources and proposed discharge locations are listed in Table 2-1, and shown graphically in Appendix A. The amount of water from each source would vary, but the total quantity introduced under the Proposed Action would not exceed a combined volume of 30,000 AF in a given year. Prior to introduction, all wells would be tested to demonstrate compliance with then-current water quality standards for conveyance of non-Project water in the San Luis Canal. Water coming from the Mendota Pool would be tested at the laterals discharging to the San Luis Canal. 3 Draft EA-15-001 Non-CVP water introduced into the San Luis Canal would either be directly delivered to agricultural users located downstream of the points of introduction, or operationally exchanged with Reclamation for a like amount, less conveyance losses, of Westlands Water District’s available water supplies in San Luis Reservoir. Exchanged water would either be delivered to agricultural users located upstream of the points of introduction in Westlands Water District or stored in San Luis Reservoir as non-CVP water for later delivery to Westlands Water District via the San Luis Canal. Introduction of Westland Water District’s non-CVP water and storage of the exchanged water would be scheduled annually with Reclamation and would be subject to excess capacity, operational constraints, and environmental requirements, as applicable. No Project Use Power would be used for the Proposed Action. It is Westlands Water District’s